Phenol condenses with phthalic anhydride in the presence of conc. $H_2SO_4$ to form:

Among the following,which is least acidic?

Given below are two statements:
Statement $I$: Phenol on treatment with $CHCl_3 / aq. KOH$ under refluxing condition, followed by acidification produces $p$-hydroxybenzaldehyde as the major product and $o$-hydroxybenzaldehyde as the minor product.
Statement $II$: The mixture of $p$-hydroxybenzaldehyde and $o$-hydroxybenzaldehyde can be easily separated through steam distillation.
In the light of the above statements, choose the correct answer from the options given below:

Which of the following fact$(s)$ explain$(s)$ why $p-$nitrophenol is more acidic than phenol?
$I$. $-I$ Effect of the nitro group.
$II$. Greater resonance effect of the $p-$nitrophenoxy group.
$III$. Steric effect of the bulky nitro group.

In which of the following reactions does carbon$-$carbon bond formation take place?

Which reagent is used in the conversion of phenol to picric acid?